The 23-year-old actress said in an Instagram post Monday she is ending her "obsession" with being thin after consulting a naturopath about her "anxiety around food."

"She phrased a pivotal question in such a way that struck a chord with me: what other things could you be thinking about if you didn't spend all your time thinking about your diet? I suddenly remembered all the activities I love that used to occupy my time," Mendes wrote.

"At some point in my life, I allowed my obsession with being thin to consume me, and I refused to make room in my mind for any other concerns," she said. "Somehow I had stripped myself of all the pastimes that brought me joy, and all that was left of me was my anxiety around food."

Mendes said she came to recognize that "body type is subject to genetics" and different for each person. This knowledge led her to reject "the toxic narrative" that "being thin is the ideal body type."

"I'm done believing in the idea that there's a thinner, happier version of me on the other side of all the tireless effort," the star wrote. "A healthy body is the ideal body type, and that will look different for every person. I'm #donewithdieting."

Mendes told fans in a post in October that she had started working with Project HEAL, an organization that helps people with eating disorders pay for treatment. She said she herself has "suffered symptoms" of an eating disorder at points in her life.

"I can say from experience that eating disorders are serious mental illnesses," the actress said. "Growing up, I watched my big sister suffer from one for many years, and I've experienced periods of my life when I've suffered symptoms as well."

Mendes plays Veronica Lodge on Riverdale, which is in the midst of a second season on The CW. The series co-stars KJ Apa as Archie Andrews, Lili Reinhart as Betty Cooper and Cole Sprouse as Jughead Jones.